I know you are not my Doctor etc.
I have been taking 20 mg of Zocor for years. This month when I went for the annual blood tests the results showed high cholesterol. The Doc is switching me to Lipitor. What happened? Did the Zocor just stop working?
It is possible. My Dad was the other way – on Lipitor with good results for a time and then the numbers crept up even though the rest of his life (exercise, diet, etc) was about the same. He got switched to another med (forget for sure which) and the numbers went back down.
I have no idea.
I once had a coworker who is diabetic. She said insulin worked great for years to help her control her blood sugar. Then she went on a vacation for a few weeks and forgot her insulin. Ever since the insulin didn’t control her blood glucose nearly as well. Something about not taking insulin for a few weeks permanently changed how her body responded to it.
I have no idea honestly. It isn’t like your body can mutate your hmg coa enzyme to make the drug less effective. But obviously your body is responding differently.
I’ve also heard stories like this about antidepressants and many other drugs. They work great, but for some people after a few years the drug stops working. At that point usually the patient and doctor either raise the dose or try a different drug.
But as to why your body adjusts to the drug, I don’t know. Who knows what feedback mechanisms the body use using.